"We cannot say that this music was – it perpetually is." – Grant Hiroshima.
Abstraction was debatably the 20th century's greatest gift to music, wresting it from the polarity of major and minor keys and their Romantic-era emotional associations. Though few composers practiced the aesthetic purely and consistently as the 19th century finally crashed to a close in World War I, abstraction was a bedrock, and one that was consciously devised – as characterized in the Museum of Modern Art's show Inventing Abstraction: 1910-1925. Some composers, though, were headed that direction for a good long time through alternative routes — discovery, evolution and technology — all with the end result of creating music whose abstract open-endedness keeps it in the present tense.
The scene was partly set by the visual arts: The need for picturesque landscape painting was usurped by photography and motion pictures. Representations of reality were well in hand. Concurrently, musical systems in place at least since the time of J.S. Bach seemed exhausted. It was Arnold Schoenberg (1874-1951), as illustrated by his Five Pieces for Orchestra, who most decisively broke away from traditional functional harmony, writes composer David Lang in his essay "Colors and Games: Music and Abstraction" (published in the MoMA catalogue for Inventing Abstraction).
That composer's move to atonality — along with serialism, the later-devised method of codification — not only did away with major/minor polarities but musical events (exposition, recapitulation, sequential repetition, etc.) that give music its narrative. Even Debussy (1862–1918), who loosening the bounds of functional harmony in the 1890s, maintained an attachment to musical description, as in Syrinx, the solo flute work inspired by the Pan and Syrinx myth. But the music's otherworldliness — one audible symptom of abstraction — wasn't possible in an earlier harmonic vocabulary.
Artists of the previous generation, however, gravitated towards abstraction by natural progression. As the aging Claude Monet (1840–1926) was losing eyesight due to cataracts, his paintings increasingly dissolved formal objects. Musically, he was mirrored by his almost exact contemporary, Gabriel Fauré (1845-1924), whose late-period String Quartet, Op. 121 reconciles form by draining its earthly dramatic contrast, achieving abstraction through asceticism. Not so similarly, Maurice Ravel (1875–1937) went far afield from his trademark tone painting by meeting the innate demands for two linear instruments in his 1922 Sonata for Violin and Cello, taking him into the realm of abstract interplay.
One of the stickier questions here is what does musical abstraction express? In theory, abstraction can express nothing but itself. Composers weren't about to settle for that — excepting the explosively terse Anton Webern (1883–1945) — particularly since loosening tonal centers was associated with madness. In the harmonically conservative genre of bel canto opera, music suddenly has greater fantasy when the opera's heroine loses her grip. With complete atonality, Schoenberg characterized the fractured mind of a murderess in the mono-drama Erwartung and further employed speech-song vocal lines in Pierrot Lunaire, whose title character has gone mad from moonbeams, or, "the wine that only eyes can drink."
Occupying a middle ground between Brahms and Schoenberg, Alban Berg (1885–1935) has his share of madness in Wozzeck, but also uses atonally to characterize physicians and military authorities unmoored from any ethical codes, not to mention their own humanity. Though hardly abstract, this story (which dates back to the Georg Büchner's 1837 play) couldn't have been told so powerfully were it not standing on the shoulders of abstraction.
Igor Stravinsky (1882-1971) needed musical events to depict human sacrifice in The Rite of Spring. But his nod to abstraction was music that exploded beyond any received ideas of proportion and narrative. Notes are repeated with manic obsessiveness. Ideas bludgeon each other. In contrast, the old-guard Richard Strauss (1864-1949) had harmonic vocabulary to keep up with Stravinsky in his Alpine Symphony but remains more conservative due to the interior logic that guides transitions from event to event – an aesthetic dating back at least to Mozart.
Beyond Stravinsky and well beyond Strauss, there was the even more radical Edgard Varèse (1863-1965) whose Hyperprism has Stravinsky's unrelieved dissonance but has no narrative. Instead, the piece seems to examine a single though complex musical object that is viewed from different angles but ones that abruptly butt into each other. Abstraction indeed. And musical Cubism as well?
Another outgrowth of this nexus are musical collages: Leos Janacek (1854-1928) eclipses Stravinsky with the invasion of foreign musical elements in his String Quartet No. 1. The impulsive physicality of Bela Bartok (1881-1945) in his String Quartet No.2 draws, like Janacek, from folk elements that were blissfully ignorant of the ancient Greek proportions that guided more cultivated art with an invisible hand. Throwing it off yielded alien musical shapes that can be heard as abstraction.
Technology at its most primitive accounts for the most obscure corner of the abstraction age. Microtones were possible with a re-tuned piano, but ended up sounding vaguely out of tune in Three Quarter-Tone Pieces by Charles Ives (1874-1954). Ballet Mécanique, the score that George Antheil (1900-1959) wrote for the 1924 experimental film of the same title, is played by a battery of player pianos, producing a cacophony that's perhaps more a statement about mechanization than music. Henry Cowell (1897-1965) discovered spooky effects by manipulating the insides of the piano in The Banshee. The Italian Russolo brothers (Antonio and Luigi) went beyond scales and notes by inventing a noise machine called the "intonarumon" that, in the original 1920s recordings, are like sound effects in a carnival spook house. Such were the utopian daydreams of Futurist movement, which has a certain crackpot element, including a belief that war was hygienic. Luckily, such ideas had a high fatality rate.